Inside the world's richest apartment building could be the birth of New York City's very own version of the "Bling Ring," where high-profile Hollywood celebrities had their valuables swiped from their homes. In the case of 740 Park Avenue's residents, jewelry is being taken from the homes of Manhattan's elite.

Thieves breaking in and pilfering jewelry from the building's multimillionaire residents at first went unreported. But with more than $300,000-worth of jewelry missing from four reported incidents on the third, sixth and 14th floors, the NYPD has opened an investigation to help the super rich protect and, hopefully, recover their valuable belongings.

The NYPD said it would not release the names of the victims until the 19th Precinct closes its investigation -- but past residents of the building have included Vanderbilts and Rockefellers, according to a published report.

The four reported incidents are believed to have been separate break-ins, according to NYPD Sgt. Lee Jones. Police are investigating to find possible repeating patterns.

Nobody knows if the thieves are coming from outside or within, police said. It's all still a mystery and there have yet to be any arrests.

In the first incident, reported on June 26, $100,000-worth of jewelry apparently went missing between May 30 and June 6, police said. In the second incident, also reported on June 26, according to police, $75,000-worth of jewelry was stolen from the sixth floor sometime between June 10 and June 16. Between May 31 and June 19, $82,000-worth of jewelry went missing, though the crime was not reported until July 16, police said. Finally, they added, sometime between June 16 and July 4, and reported on July 30, $53,000-worth of jewelry disappeared.

The building's manager, Brown Harris Stevens Residential Management, acknowledged the investigation in a written statement: "On behalf of the board and management of 740 Park Avenue, we can confirm that there is an ongoing investigation and that we are cooperating with the authorities."

Though the financially exclusive apartment building, located on the corner of Park Avenue and 71st Street, is home of Manhattan's elite, many people have access, including service staff and building workers.

Missing items include watches, bracelets, and other pieces of precious jewelry, according to published reports.

The building was originally constructed by Jacqueline Kennedy Onassis's grandfather in 1929. Jackie O's childhood home is now home to the wealthiest of New York's wealthy. Past and present residents have included some of the most powerful of New York's old-money families - including members of the Vanderbilt, Rockefeller, Bouvier, Chrysler and Houghton clans, just to name a few, according to a book on the exclusive residence, "740 Park," by Michael Gross.